I've been researching this for over a week & my brain is mush.

My current 755 setup is

Intel Core 2 Duo E6400

2GB Memory

Radeon HD 4650

160GB - Windows XP SP3/All current drivers & updates

1TB SATA

2TB SATA

BIOS - A22

I've been looking to see the fastest processor this motherboard ( OGM819 w/Q35 chipset).  I've found a ton of info but no definitve answer.  I believe that an E8400 is the fastest & in my price ranges.  So 1A. Is this the fastest CPU I can upgrade too?  1B. Will the stock heatsink & power supply do or will they need upgrading also?  If so what power supply will I need?  To add to this I found a thread somewhere that stated I could upgrade to a 64 bit CPU, is this correct & what would you recommend?

2. Memory - the software I downloaded from Dell - 'My Dell' states that I can upgrade to 8GB but looking further my current setup, 32 bit will only see 4 GB, correct? So the only way to upgrade to 8GB is via a 64 bit CPU, correct again?

Why am I doing this.  I'm ripping my blue-ray collection to this pc which is now my HTPC.  3TB looks huge but not when you rip uncompressed iso.  What I'm running into is that I'm compressing some of this isos to BD25 to save space but the process is taking up to 11 hours with the current setup.  Any & all suggestion are extremely welcomed.  While my 755 just sits there I want to speed up the process as much as I can.

Thank you all in advance.

Thom